|Overview||Chronicles tech tree||Bronze Dawn tech tree|
Towers are a static point defence and serve many useful purposes. They can be built anywhere so long as that area is enclosed within your borders, and can also be garrisoned with extra troops to heal the units within as well as enhance the tower's fighting ability. Garrisoning extra troops normally results in extra arrows. The number of projectiles a tower can fire at opponents is normally three. Additionally, they also conduct research into Attrition, which increases the amount of Attrition damage which enemy units suffer without proper support in your territory. Because the first unit available to most factions for raiding and conquering are Peasant Levy, it is thus imperative that if you're going to turtle (and build Wonders) early on, that you must have access to Towers and obtain Attrition research as quickly as possible, unless you are playing as Russia.
Towers, however, have their drawbacks. They can only fire on units which are visible; they are unable to detect hidden units such as spies or Orsini archers, thus you will need to build a series of outposts nearby, or keep spies and scout units near to detect them. Equally, they are also not effective against siege weapons, heavy infantry or war elephants.
In the Castle Age, towers will be upgraded automatically to a different structure: the Keep. Keeps have more hitpoints, more armour and better line of sight. You must build a Fort and research Fortifications there first in order to upgrade your Towers.
The researching of Imperial Mandate by Orthodox or Asiatic factions during the Castle Age upgrades Keeps into Bastions which are substantially stronger, and fire more devastating projectiles on opponents. Additionally, a Bastion also has a more powerful range, thus making it more effective at point defence.
Attrition upgrades increase the damage that enemy units will suffer in your territory, and are also required for some militia units.
Note: Level 4 is attainable only with Imperial Mandate.
Although normally built by Orthodox and Eastern factions, Bastions are often found in the lands of various Catholic subfactions, such as the Dutch, the Italian city-states and the Maqurrans. Bastions also dot the landscape of Northern Britain in Renovatio Europam.
In some parts of Northern China, the Great Wall is represented by the presence of Bastions.